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Finding the Fourth Proportional to 30.70, 45.98 and 21.57

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Solution

The fourth proportional to 30.70, 45.98 and 21.57 is: 32.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.70 : 45.98 = 21.57 : x
  2. Step 2: Convert to fraction form
    30.70/45.98 = 21.57/x
  3. Step 3: Cross multiply
    30.70x = 45.98 × 21.57
  4. Step 4: Simplify right side
    30.70x = 991.97
  5. Step 5: Solve for x
    x = 991.97/30.70
  6. Step 6: Final answer
    x = 32.31

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.